874 FXUS63 KFGF 251258 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 658 AM CST Fri Dec 25 2020 .UPDATE... Issued at 658 AM CST Fri Dec 25 2020 Mostly clear skies with a bit of cirrus over the northeastern counties. Red River and points eastward continue to have southerly winds and temperatures in the single digits either side of zero. Farther west over the Devils Lake Basin, winds have already gone southwesterly or westerly, and temps have risen into the teens to low 20s. Warm in the west and cooler and the east will continue for much of the day, with the mild air pushing into the Red River Valley by afternoon. && .SHORT TERM...(Today through Saturday) Issued at 246 AM CST Fri Dec 25 2020 Temperatures will be the main challenge for the period. Northwesterly flow aloft transitioning to brief ridging will continue to keep things fairly quiet for the short term. A narrow band of stratus moving across our eastern counties on the leading edge of some warm air advection. The thermal ridge will push out into our area early today, and even after the trough axis passes by there will be good warming thanks to southwest to westerly winds. A decent amount of sunshine with some cirrus moving in from the west. Still uncertain if the warmer temps will make it into the Red River Valley, but with a southwesterly fetch do think that there will be enough mixing to get into the upper 20s and even low 30s. Colder further east where they will have a lower starting point and some lingering clouds. Weak surface high pressure tonight will allow light and variable winds and temps down into the single digits even with a more mild air mass. The surface high will move off to the east during the day on Saturday, with winds becoming southerly as a trough develops to our west. Increasing cloud cover and a southeasterly wind direction will keep temps a bit cooler than today, with highs only in upper teens to the 20s. .LONG TERM...(Saturday night through Thursday) Issued at 246 AM CST Fri Dec 25 2020 Summary... A ridge continues to build into the central United States through the early part of the weekend, with a short wave translating across the Northern Plains Sunday. Chances for snow increase across the forecast area Sunday, with light accumulations. Conditions clear out by early next week before a larger system moves into the Central Plains by the mid to later part of next week. There's uncertainty with system as ensembles are in disagreement in strength, development, and track. Impacts remain minimal for snow chances on Sunday. Sunday through Monday... A short wave moves through the Northern Plains during the day on Sunday, increasing the chances for snow across the forecast area. Moisture and lift are available across the area, with snow ratios on the higher end. Confidence has grown throughout the day on the chances for snow across the forecast area, with light accumulations. Snow ratios and moisture content will help determine the total accumulations. Confidence is on the lower end for snow amounts. The low end scenario would be less than an inch of accumulations, with a high end toward 2 inches. Consensus between modules indicate 1-2 inches as the best possibility for snow accumulations for the forecast area. Besides chances for snow, temperatures will be on the seasonal side before dropping to upper single digits and lower teens for Monday daytime highs. Cold air advection sweeps into the Northern Plains Monday allowing for drier conditions ahead of an approaching system by the middle part of the week. Tuesday and onward... Ensembles have indicated a trough developing and digging deep into the SW United States mid next week. Confidence is high that the system will develop, but that begins to decrease when we talk about track and development. A lot of uncertainty surrounds the development of the system and if it can mature quick enough while it approaches the central United States. Some ensembles show a negative tilt to the structure of the system at the 500mb level indicating the system weakening over the plains before being absorbed into the flow in Canada. Atmospheric soundings indicate strong lift and moisture content through the 700mb level across a majority of the plains. Over the past 24 hours ensembles have been slowly pushing the system further toward the north wrapping in cold air from Canada and pushing moisture content further into North Dakota and western Minnesota, increasing chances for snow. What the models have agreed on is the track being somewhere over the Upper Mississippi River Valley. Snow amounts and development are still in question and will need to be further studied over the weekend to determine impacts to the region. At this time, the best chances for snow look to remain in Minnesota possibly affecting SE portions of the forecast area. && .AVIATION...(For the 12Z TAFS through 12Z Saturday morning) Issued at 526 AM CST Fri Dec 25 2020 VFR conditions at all TAF sites with only a few cirrus clouds across the area. Winds will shift from a more southerly direction to southwesterly this morning, picking up a bit into the 10 to 15 kt range. By early afternoon, winds will shift to the northwest with some gusts above 20 kts. Winds will diminish by the evening. There are some indications of some stratus coming down into our MN airports by the end of the period, so included some MVFR conditions. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. $$ UPDATE...JR SHORT TERM...JR LONG TERM...Spender AVIATION...JR